Elastomeric endless power transmission belts are well known and widely used in apparatus such as yarn-processing machines, combustion engines, and vacuum sweepers. Historically, drive belts were made from leather or cloth belting sewn together at the ends to define an endless loop. Over time, more elastic and less expensive materials, i.e. synthetic rubber, has been substituted for leather and cloth in the manufacture of drive belts.
Modern vacuum sweeper belts are typically cylindrical or rectilinear in shape to maximize the surface of the belt which drivingly engages the brush roll of the sweeper. The belt drive surface is usually smooth, unperforated and free of any traction enhancing features. One historical problem with the design of vacuum sweeper drive belts is caused by the collection of dirt, hair carpet fibers and other foreign matter on the brush roll during operation of the sweeper. The matter works its way between the drive surface of the belt and the bunch roll reducing the traction, and increasing the slippage, of the drive belt on the brush roll. The reduced traction results in slower revolutions of the brush roll during sweeper operation, significantly decreasing the volume of dirt and other matter picked up by the sweeper.
A variety of drive belts have been designed to overcome specific problems with the apparatus on which they are deployed. U.S. Pat. No. 4,034,615 discloses a drive belt having rhomboidally or trapezoidally shaped teeth disposed on the belt drive surface which operates without creating the siren-like noise characteristic of toothed belts.
The apparatus disclosed in U.S. Pat. No. 3,129,553 is designed to prevent the accumulation of lint on a spindle drive tape during the operation of yarn-processing machines by passing the drive surface of the tape over an idler roll having knurled surface. The knurled surface and the centrifugal force of the idler roll contact to remove lint from the tape surfaces.
U.S. Pat. No. 2,912,722 discloses a drafting apron having a plurality of ribs disposed on the apron drive surface. The ribs extend diagonally along the inner surface of the apron to define a criss-cross diamond-like pattern on the inner surface of the apron.
None of the aforementioned belt features have been applied to vacuum sweeper drive belts to improve belt traction on the vacuum brush roll to eliminate the negative effects of unwanted matter accumulation on the roll.